PURPOSE: To provide a metal protective composition which has sufficient adhesive property to metal, can be coated as a solution of high solid content, and is especially suitable for primer coating of automobile for chipping and corrosion prevention, by blending a basic calcium sulfonate and a specified terpolymer.

CONSTITUTION: A metal protective composition comprising (A) 10-90 parts by weight of a basic calcium sulfonate and (B) 90-10 pt.wt. of a terpolymer which consists of 50-99 wt.% of a 2-4C olefin, 1-30 wt.% of an unsaturated ester consisting of a carboxylic acid vinyl ester or an ester of an acrylic acid or a methacrylic acid, and 1-20 wt.% of an unsaturated carboxylic acid. The terpolymer preferably consists of ethylene, vinyl acetate, and acrylic acid or methacrylic acid. The above-mentioned composition can dissolve in a common solvent to give a solution containing more than 60 wt.% of a solid.